MX469P - CML Microcircuits (USA) Inc.

DATA BULLETIN

MX469 1200/2400/4800bps MSK Modem

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

Features Applications

 Selectable Data Rates

1200/2400/4800bps

 Full-Duplex MSK

 RX and TX Bandpass Filters

 Clock Recovery and

Carrier Detect Capabilities

 Pin Selected Xtal/Clock Inputs

1.008MHz or 4.032MHz

 Radio and General Applications

 Data-Over-Radio

 PMR/Cellular Signaling

 Portable Data Terminals

 Personal/Cordless Telephone

CLOCK

OSCILLATOR DIVIDER

DATA

LATCH

DIGITAL

PLL

RECTIFIER

S/N

COMPARATOR

NOISE FILTER RECTIFIER

RX FILTER

RX ENABLE DATA

FILTER

DIGITAL

FILTER

LIMITER LIMITER

RETRIGGERABLE

MONOSTABLE

TX GENERATOR

XTAL/CLOCK

CLOCK RATE

TX DATA I/P

RX SIGNAL I/P

TX SIGNAL O/P

UNCLOCKED

DATA O/P

CLOCKED

DATA O/P

RX SYNC O/P

BANDPASS O/P

CARRIER DETECT O/P

CARRIER DETECT TIME CONSTANT

TX SYNC O/P

TX FILTER

XTAL

.. n

BIAS

4800 BPS SELECT

TX ENABLE

1200/ BPS SELECT2400

The MX469 is a full-duplex pin-selectable 1200/2400/4800bps Minimum Shift Key (MSK) Modem for FM radio

links. The mark and space frequencies are 1200/1800, 1200/2400, and 2400/4800Hz respectively. Tone

frequencies are phase continuous; transitions occur at the zero crossing point. The use of a common Xtal

oscillator with a choice of two clock frequencies (1.008MHz or 4.032MHz) provides data-rate, transmit

frequencies, and RX/TX synchronization. The transmitter and receiver operate entirely independently

including individual section powersave functions.

The MX469 includes on-chip circuitry for Carrier Detect and RX Clock Recovery, both of which are made

available at output pins. RX, TX, and Carrier Detect circuits contain bandpass filters to provide high quality

signals in their respective paths. The carrier detect time constant is set by an external capacitor, whose value

should be arranged as required to further enhance this product's performance in high-noise environments.

The MX469 demonstrates high sensitivity and good bit-error-rate under adverse signal conditions.

This low-power device requires few external components and is available in the following packages:

24-pin SOIC (MX469DW), 22-pin PDIP (MX469P), and 20-pin SOIC (MX469D3).

MX469P package discontinued

1200/2400/4800bps MSK Modem 2 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

Contents

Section Page

1. Block Diagram................................................................................................................3

2. Signal List.......................................................................................................................4

3. External Components....................................................................................................6

4. General Description.......................................................................................................7

4.1 Timing.................................................................................................................................. 7

4.1.1 1200bps ..................................................................................................................................7

4.1.2 2400bps ..................................................................................................................................8

4.1.3 4800bps ..................................................................................................................................9

5. Application ...................................................................................................................10

5.1 Synchronous Modem Design Considerations ................................................................... 10

5.2 Bit Error Rate..................................................................................................................... 11

6. Performance Specifications........................................................................................12

6.1 Electrical Specifications..................................................................................................... 12

6.1.1 Absolute Maximum Limits.....................................................................................................12

6.1.2 Operating Limits....................................................................................................................12

6.1.3 Operating Characteristics......................................................................................................13

6.1.4 Packages ..............................................................................................................................15

MXCOM, Inc. reserves the right to change specifications at any time and without notice.

MX469P package discontinued

1200/2400/4800bps MSK Modem 3 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

1. Block Diagram

CLOCK

OSCILLATOR DIVIDER

DATA

LATCH

DIGITAL

PLL

RECTIFIER

S/N

COMPARATOR

NOISE FILTER RECTIFIER

RX FILTER

RX ENABLE DATA

FILTER

DIGITAL

FILTER

LIMITER LIMITER

RETRIGGERABLE

MONOSTABLE

TX GENERATOR

XTAL/CLOCK

CLOCK RATE

TX DATA I/P

RX SIGNAL I/P

TX SIGNAL O/P

UNCLOCKED

DATA O/P

CLOCKED

DATA O/P

RX SYNC O/P

BANDPASS O/P

CARRIER DETECT O/P

CARRIER DETECT TIME CONSTANT

TX SYNC O/P

TX FILTER

XTAL f

.. n

BIAS

4800 BPS SELECT

TX ENABLE

1200/ BPS SELECT2400

Figure 1: Block Diagram

MX469P package discontinued

1200/2400/4800bps MSK Modem 4 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

2. Signal List

Signal Type Description

PDWD3

1 1 1 Xtal/Clock input The input to the on-chip inverter, for use with either a

1.008MHz or a 4.032MHz Xtal or external clock. Clock

frequency selection is by the “Clock Rate” input pin. The

selection of this frequency will affect the operational Data

Rate of this device. Refer to Table 3. Operation of any

MX•COM IC without a Xtal or clock input may cause

device damage. To minimize damage in the event of a

Xtal/drive failure, it is recommended that a current

limiting device (resistor or fast-reaction fuse) be installed

on the power supply (VDD).

22 2 Xtal output Output of the on-chip inverter.

3 3 3 TX Sync output A squarewave, produced on-chip, to synchronize the

input of logic data and transmission of the MSK signal

(See Figure 3).

5 5 4 TX Signal output When the transmitter is enabled, this pin outputs the

(140-step pseudo sinewave) MSK signal (See Figure 3).

With the transmitter disabled, this output is set to a high-

impedance state.

6 7 5 TX Data input Serial logic data to be transmitted is input to this pin.

78 6 EnableTX Input A logic ‘0’ will enable the transmitter (See Figure 3). A

logic ‘1’ at this input will put the transmitter into

powersave while forcing “TX Sync Out” to a logic ‘1’ and

“TX Signal Out” to a high-impedance state. This pin is

internally pulled to VDD.

8 9 7 Bandpass output The output of the RX Bandpass Filter. This output

impedance is typically 10k and may require buffering

prior to use.

9 10 8 RX Enable Input The control of the RX function. The control of other

outputs is provided in Table 2

10 11 9 VBIAS power The output of the on-chip analog bias circuitry. Held

internally at VDD/2, this pin should be decoupled to VSS

by a capacitor (C2). See Figure 2 and RX Enable notes.

This bias voltage is maintained under all powersave

conditions.

11 12 10 VSS power Negative supply (GND).

12 13 11 Unclocked Data output The recovered asynchronous serial data output from the

receiver.

13 14 12 Clocked Data output The recovered synchronous serial data output from the

receiver. Data is latched out by the recovered clock,

available at the “RX Sync O/P”. (See Figure 4 and

Figure 6).

14 15 13 Carrier Detect output For 1200 and 2400bps operation only. When an MSK

signal is being received this output is a logic ‘1’. The

Carrier Detect signal should be ignored during 4800bps

operation.

15 16 14 RX Signal input The MSK signal input for the receiver. This input should

be coupled via a capacitor, C3.

MX469P package discontinued

1200/2400/4800bps MSK Modem 5 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

Signal Type Description

PDWD3

17 18 15 RX Sync output A flywheel squarewave output. This clock will

synchronize to incoming RX MSK data. (See Figure 4

and Figure 6).

16 19 16 1200/2400BPS

Select input A logic ‘1’ on this pin selects the 1200bps option; tone

frequencies are one cycle of 1200Hz represents a logic

‘1’, one-and-a-half cycles of 1800Hz represents a logic

‘0’. A logic ‘0’ on this pin selects the 2400bps option;

tone frequencies are one-half cycle of 1200Hz represents

a logic ‘1’, one cycle of 2400Hz represents a logic ‘0’.

This pin has an internal 1M pull-up resistor.

Operational Data Rate Configurations are illustrated in

Table 3

18 20 17 4800 BPS Select input A logic '1' on this pin combined with a logic '0' on the

1200/2400 BPS Select pin will select the 4800 option

(1M pulldown resistor). Tone frequencies are: one-half

cycle of 2400Hz represents a logic '1', one cycle of

4800Hz represents a logic '0'. This state can only be

achieved using a 4.032MHz Xtal input. Operational Data

Rate Configurations are illustrated in Table 3

19 21 18 Clock Rate input A logic input to select and allow the use of either a

1.008MHz or 4.032MHz Xtal/clock. Logic ‘1’ =

4.032MHz, logic ‘0’ = 1.008MHz. This input has an

internal pulldown resistor (1.008MHz).

20 23 19 Carrier Detect

Time Constant output Part of the carrier detect integration function. The value

of C4 connected to this pin will affect the carrier detect

response time and therefore the noise performance (See

Figure 2, Note 3).

22 24 20 VDD power Positive supply. A single 5-volt supply is required.

21 4, 6,

17,

N/C No Internal Connection.

Table 1: Signal List

RX Enable = RX Function Clock Data Output Carrier Detect Rx Sync Out

1 = Enabled Enable Enabled Enabled

0 = Powersave 0 0 1 or 0

Table 2: RX Enable Control Functions

XTAL/CLOCK Frequency 1.008MHz 4.032MHz

Clock Rate pin 00111

1200/2400 Select Pin 10100

4800 Select Pin 00001

Data Rate (bps) 1200 2400 1200 2400 4800

Table 3: Operational Data Rate Configuration

MX469P package discontinued

1200/2400/4800bps MSK Modem 6 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

3. External Components

MX469

XTAL/CLOCK

TX SYNC OUT

TX SIGNAL OUT

TX DATA IN

BANDPASS OUT

RX ENABLE

UNCLOCKED DATA OUT

CLOCKED DATA OUT

RX SIGNAL IN

CARRIER DETECT OUT

RX SYNC OUT

BIAS

X1 XTAL

TX ENABLE

4800 BPS SELECT

CLOCK RATE

CARRIER DETECT TIME CONSTANT

1200/ BPS SELECT2400

Figure 2: Recommended External Components

Component Notes Value Tolerance

R1 1.0M±10%

C1 33pF ±5%

C2 1.0µF ±20%

C3 0.1µF ±20%

C4 Note 1 0.1µF ±10%

C5 Note 2 1.0µF ±25%

C6 Note 3 33pF ±5%

C7 Note 2 1.0µF ±20%

X1 Note 4 1.008MHz or 4.032MHz See ‘Clock-Rate’ Pin

Table 4: Recommended External Components

Notes:

1. The value of C4 determines the Carrier Detect time constant. A long time constant results in improved

noise immunity but increased response time. C4 may be varied to trade-off response time for noise

immunity.

2. Decoupling circuits depend upon whether the input signal is referenced to VBIAS or VSS. Use C5 when

the input signal is referenced to VBIAS. Use C7 when the input signal is referenced to VSS. It is not

necessary to use both C5 and C7.

3. C6 reduces Xtal voltage overshoot. Reference the MX-COM Xtal Application Note.

4. For best results, a crystal oscillator design should drive the clock inverter input with signal levels of at

least 40% of VDD, peak to peak. Tuning fork crystals generally cannot meet this requirement. To

obtain crystal oscillator design assistance, consult your crystal manufacturer.

MX469P package discontinued

1200/2400/4800bps MSK Modem 7 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

4. General Description

4.1 Timing

4.1.1 1200bps

Characteristics Note Min. Typ. Max. Unit

TX Enable to TX Sync Rise Time tSYNC 416 µs

TX Delay, Signal to Disable Time tESET 2.0 800 µs

Data Set-Up Time tDSET 12.0 µs

Data Hold Time tDH 2.0 µs

TX Delay to O/P Time tTXD 1.2 µs

TX Data Rate Period tTDR 833 µs

RX Data Rate Period tRDR 800 865 µs

Undetermined State 2.0 µs

Internal RX Delay tID 1.5 ms

Notes:

1. Consider the Xtal/clock tolerance.

2. All TX timings are related to the TX Sync Output.

ENABLE

SYNC

TX DATA

1200 BPS

TX OUTPUT

OPEN CIRCUIT OPEN CIRCUIT

DC = Don't Care

DV = Data Valid

DC DV

DC DC

ESET

TXD

DSETDSET

TDR

SYNC

Figure 3: Transmitter Timing: 1200bps

SIGNAL I/P

1200 BPS

SYNC O/P

(1200Hz)

CLOCKED

DATA O/P

LOGIC '1'

RDR Undetermined

State

LOGIC '0'

LOGIC '1' LOGIC '0'

Figure 4: Receiver Timing Diagram: 1200bps

MX469P package discontinued

1200/2400/4800bps MSK Modem 8 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

4.1.2 2400bps

Characteristics Note Min. Typ. Max. Unit

TX Enable to TX Sync Rise Time tSYNC 208 µs

TX Delay, Signal to Disable Time tESET 2.0 400 µs

Data Set-Up Time tDSET 12.0 µs

Data Hold Time tDH 2.0 µs

TX Delay to O/P Time tTxD 1.2 µs

TX Data Rate Period tTDR 416 µs

RX Data Rate Period tRDR 400 433 µs

Undetermined State 2.0 µs

Internal RX Delay tID 1.5 ms

Notes:

1. Consider the Xtal/Clock tolerance.

2. All TX timings are related to the TX Sync Output.

ENABLE

SYNC

TX DATA

2400 BPS

TX OUTPUT

OPEN CIRCUIT OPEN CIRCUIT

DC = Don't Care

DV = Data Valid

DV DV

DC DV DV

DC DC DV DV

DC DC DC DC

ESET

TXD

DSETDSET

SYNC

TDR

Figure 5: Transmitter Timing: 2400bps

SIGNAL I/P

2400 BPS

SYNC O/P

(2400Hz)

CLOCKED

DATA O/P

LOGIC '1' LOGIC '1'

RDR Undetermined

State

LOGIC '0' LOGIC '0'

LOGIC '1' LOGIC '1'LOGIC '0' LOGIC '0'

Figure 6: Receiver Timing: 2400bps

MX469P package discontinued

1200/2400/4800bps MSK Modem 9 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

4.1.3 4800bps

Characteristics Note Min. Typ. Max. Unit

TX Enable to TX Sync Rise Time tSYNC 104 µs

TX Delay, Signal to Disable Time tESET 2.0 200 µs

Data Set-Up Time tDSET 12.0 µs

Data Hold Time tDH 2.0 µs

TX Delay to O/P Time tTxD 1.2 µs

TX Data Rate Period tTDR 208 µs

RX Data Rate Period tRDR 200 216 µs

Undetermined State 2.0 µs

Internal RX Delay tID 1.0 ms

Notes:

1. Consider the Xtal/Clock tolerance.

2. All TX timings are related to the TX Sync Output.

ENABLE

SYNC

TX DATA

4800 BPS

TX OUTPUT

OPEN CIRCUIT OPEN CIRCUIT

DC = Don't Care

DV = Data Valid

DV DV

DC DV DV

DC DC DV DV

DC DC DC DC

ESET

TXD

DSETDSET

SYNC

TDR

Figure 7: Transmitter Timing: 4800bps

SIGNAL I/P

4800 BPS

SYNC O/P

(4800Hz)

CLOCKED

DATA O/P

LOGIC '1' LOGIC '1'

RDR Undetermined

State

LOGIC '0' LOGIC '0'

LOGIC '1' LOGIC '1'LOGIC '0' LOGIC '0'

Figure 8: Receiver Timing: 4800bps

MX469P package discontinued

1200/2400/4800bps MSK Modem 10 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

5. Application

5.1 Synchronous Modem Design Considerations

The MX469 is an easily applied data pump, which can be used with many protocols. Because it is an MSK, or

minimum shift keying, modem, it achieves a more noise resistant, higher data rate in a narrower bandwidth

than other FSK (frequency shift keying) modems. This characteristic is especially important for wireless

applications because it fundamentally determines the bandwidth of RF transmissions, which are strictly limited

and controlled by regulatory agencies. Using MSK signaling, the MX469 data modem can achieve a 2400bps

data rate within the typical 300-3000 Hz voice band of many common radios.

In order to achieve this advantage, an MSK modem must precisely control the bit rate and timing of the

modulated Tx output signal bits. This control is asserted by the MSK modem with a data clock signal, which

is output, by the modem to pace the Tx data source (e.g. a microcontroller). The data clock signal, in effect,

indicates when the Tx data source should provide the next Tx data bit to the modem. See Figure 9. Because

this type of interface involves the use of a modem generated bit clock signal to control the timing of when new

Tx data bits must be supplied from the data source, the interface is called synchronous.

Another characteristic of a synchronous modem is that, to receive data, it must first learn the data bit timing of

the Rx signal stream before it can accurately demodulate Rx data bits. Accordingly, a synchronous modem

undergoes a period of training or synchronization when it first begins to receive a stream of MSK modulated

signal. During this initial receive phase, the received signal is evaluated over several bit times as the modem

‘locks on’ and achieves proper receive synchronization. The training sequence, called a preamble, is a

specific data pattern which must be added to the ‘front’ of a transmit data stream with the start of each new

transmission. A specific preamble data pattern (e.g. 16 bits of alternating 0,1,0,1… for the MX469) is used to

optimize the training accuracy while minimizing the number of preamble bits required.

Tx data

Tx SYNC

(data clock)

Data Bit Tx

Source

(e.g.µC)

011

Give me BIT 2

MSK Tx Out

MSK Modem

Transmitting

I took BIT 2

DATA: 0 1 1

Give me BIT 3

I took BIT 3

Give me BIT 1

I took BIT 1

Figure 9: Synchronous Transmit Operation

Non-synchronous or asynchronous interfaces are commonly found in wired applications which do not have

the bandwidth efficiency requirements of wireless systems. A well known example is the serial port of a

personal computer which can transmit a 1200 bps (or faster) data signal over a single Tx signal without using

an additional data clock signal to control the precise rate and timing of data bits being transmitted to a typical

telephone line data modem. Popular modem standards such as Bell 202 and v.23 use FSK signaling to pass

such asynchronous serial port data signals over telephone systems.

Another aspect of asynchronous interfaces and modems is that they can carry data streams which are not at

the exact, nominal data rate. For example, a 1200 bps FSK modem will typically operate properly when

supplied with transmit data streams of 1201 bps or 1199 bps.

Because of the differences in synchronous and asynchronous interfaces, they cannot successfully operate if

directly connected. In other words, a personal computer’s RS232 serial port cannot directly interface to an

MSK modem. This is because:

 The asynchronous interface may provide data bits too fast or too slow compared to the precise rate

required for MSK signaling (a bit rate, or pacing, incompatibility).

 The timing of each specific data bit presented by an asynchronous interface will not be aligned with the

precise bit timing required for MSK signaling (a bit timing incompatibility).

Synchronous and asynchronous interface can be successfully interfaced for applications requiring the

advantages of both. This typically involves the use of data buffering and retiming circuits to resolve the timing

and pacing issues.

MX469P package discontinued

1200/2400/4800bps MSK Modem 11 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

5.2 Bit Error Rate

ERROR

DETECTOR

MILLI-

AMMETER

TRUE RMS

VOLTMETER TRUE RMS

VOLTMETER

CARRIER

DETECT

OUT HIGH

DETECTOR

MILLI-

AMMETER

OSCILLOSCOPE

BUFFER

(INTERFACE)

CIRCUIT

VDD

DATA

I/P

Tx SYNC

SIGNAL

O/P

SIGNAL

IN RX

SYNC

CLOCKED

DATA OUT

CARRIER

DETECT

OUT

PREAMBLE &

PSEUDO-RANDOM

DATA

GENERATOR

S3 TELEPHONE

CHANNEL

SIMULATOR

(with attenuator

5kHz BW noise gen)

MX469

TRANSMITTER

(components

as Fig. 2)

MX469

RECEIVER

(components

as Fig. 2)

Figure 10: MX469 Test Set-Up

Figure 11: Typical Variation of Bit Error Rate with Input Level

MX469P package discontinued

1200/2400/4800bps MSK Modem 12 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

BIT ERROR RATE (log scale)

SNR (dB) BIT RATE BANDWIDTH (lin scale)

-5

-4

-3

-2

2x10

-2

1234 5678

910 11 12 13 14 15 16

IDEAL COHERENT MSK MX469

Figure 12: RX Bit-Error-Rate vs. Signal-to-Noise Ratio

6. Performance Specifications

6.1 Electrical Specifications

6.1.1 Absolute Maximum Limits

Exceeding these maximum ratings can result in damage to the device.

General Notes Min. Typ. Max. Units

Supply (VDD-VSS) -0.3 7.0 V

Voltage on any pin to VSS -0.3 VDD + 0.3 V

Current

VDD -30 30 mA

VSS -30 30 mA

Any other pin -20 20 mA

DW / D3 / P Packages

Derating above 25C10 mW/C above 25C

Operating Temperature -40 85 C

Storage Temperature -55 125 C

6.1.2 Operating Limits

Correct Operation of the device outside these limits is not implied.

Notes Min. Typ. Max. Units

Supply (VDD-VSS) 4.5 5.0 5.5 V

Operating Temperature -40 85 C

Xtal Frequency 1.008 4.032 MHz

MX469P package discontinued

1200/2400/4800bps MSK Modem 13 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

6.1.3 Operating Characteristics

For the following conditions unless otherwise specified.

VDD = 5.0V @ TAMB = 25C

Audio Level 0dB ref. = 300mVRMS, Xtal/Clock Frequency = 4.032MHz

Signal-to-Noise Ratio measured in the Bit-Rate Bandwidth

1200bps BRB = 1200Hz

2400bps BRB = 2400Hz

4800bps BRB = 4800Hz

Notes Min. Typ. Max. Units

Static Values

Supply Current

RX Enabled, TX Disabled 3.6 mA

RX and TX Enabled 4.5 mA

RX and TX Disabled 650 µA

Logic ‘1‘ Level 1 4.0 V

Logic ‘0’ Level 1 1.0 V

Digital Output Impedance 4.0 k

Analog and Digital Input Impedance 100 k

TX Output Impedance 0.6 1.0 k

On-Chip Xtal Oscillator

RIN 10.0 M

ROUT 10.0 k

Inverter DC Voltage Gain 10.0 V/V

Gain Bandwidth Product 10.0 MHz

Dynamic Values

Receiver

Signal Input Dynamic Range

SNR = 50dB 3, 4 100 230 1000 mVRMS

Bit Error Rate

SNR = 12dB 4 7.0 10-4

1200bps 2.5 10-4

2400bps 1.5 10-3

4800bps 1.5 10-3

SNR = 20dB 4

1200/2400/4800bps 1.0 10-8

Receiver Synchronization SNR =12dB 7

Probability of Bit 8 Being Correct 99 %

Probability of Bit 16 Being Correct 99.5 %

Carrier Detect 5, 10

Sensitivity 7, 8 150 mVRMS

Probability of C.D. Being High

After Bit 8 (1200bps) SNR = 12dB 5, 9 98 %

After Bit 16 SNR = 12dB 5, 9 99.5 %

0dB Noise No Signal 9 5 %

MX469P package discontinued

1200/2400/4800bps MSK Modem 14 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

Notes Min. Typ. Max. Units

Transmitter Output

TX Output Level 775 mVRMS

Output Level Variation

1200/1800Hz 0 ±1.0 dB

1200/2400Hz 0 ±1.0 dB

2400/4800Hz 0 ±1.0 dB

Output Distortion 3.0 5.0 %

3rd Harmonic Distortion 2.0 3.0 %

Logic ‘1’ Carrier Frequency

1200bps 6 1200 Hz

2400bps 6 1200 Hz

4800bps 6 2400 Hz

Logic ‘0’ Carrier Frequency

1200bps 6 1800 Hz

2400bps 6 2400 Hz

4800bps 6 4800 Hz

Isochronous Distortion

1200Hz - 1800Hz/1200Hz -

2400Hz 25.0 40.0 s

1800Hz - 1200Hz/2400Hz -

1200Hz 20.0 40.0 s

2400Hz - 4800Hz/4800Hz -

2400Hz 10.0 20.0 s

Operating Characteristics Notes:

1. With reference to VDD = 5.0 volts.

2. Xtal frequency (ref. Clock Rate pin), type and tolerance depends upon system requirements.

3. See Figure 4 (variation of BER with Input Signal Level).

4. SNR = Signal-to-Noise in the Bit-Rate Bandwidth.

5. See Figure 2.

6. Dependent upon Xtal tolerance.

7. 10101010101 ...01 pattern.

8. Measured with a 150mVRMS input signal (no noise).

9. Reference (0dB) level for C.D. probability measurements is 230mVRMS.

10. For 1200bps and 2400bps operation only: when operating at 4800bps the carrier detect output should

be ignored.

MX469P package discontinued

1200/2400/4800bps MSK Modem 15 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

6.1.4 Packages

Figure 13: 24-pin SOIC Mechanical Outline: Order as part no. MX469DW

NOTE : All dimensions in inches (mm.)

Angles are in degrees

Package Tolerances

TYP. MAX.MIN.DIM.

0.360 (9.14)

0.480 (12.19)

0.128 (3.25)

1.100 (27.94)

0.185 (4.70)

0.420 (10.67)

0.390 (9.91) 0.420 (10.67)

0.020 (0.51) 0.020 (0.51)

0.040 (1.02)0.066 (1.68)

1.080 (27.43)

0.330 (8.38)

0.100 (2.54)

0.045 (1.14)

0.065 (1.65)

0.015 (0.38)

0.010 (0.25)

7°

PIN 1

Figure 14: 22-pin PDIP Mechanical Outline:

Order as part no. MX469P

MX469P package discontinued

1200/2400/4800bps MSK Modem 16 MX469

1998 MX-COM, Inc. www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054 Doc. # 20480081.010

4800 Bethania Station Road, W inston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.

PIN 1

ALTERNATIVE

LOCATION

MARKING

NOTE : All dimensions in inches (mm.)

Angles are in degrees

PackageTolerances

TYP. MAX.MIN.

DIM.

0.105 (2.67)0.093 (2.36) 0.419 (10.64)

45°

7°

0° 10°

0.050 (1.27)

0.046 (1.17)

0.510 (12.95)

0.299 (7.59)

0.050 (1.27)

0.016 (0.41)

0.390 (9.90) 0.020 (0.51)0.003 (0.08)

0.009 (0.23) 0.0125 (0.32)

0.013 (0.33) 0.020 (0.51)

0.036 (0.91)

0.495 (12.57)

0.286 (7.26)

5°

Figure 15: 20-pin SOIC Mechanical Outline:

Order as part no. MX469D3

MX469P package discontinued

CML Product Data

In the process of creating a more global image, the three standard product semiconductor

companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc

(USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst

maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA)

Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML

Microcircuits.

These companies are all 100% owned operating companies of the CML Microsystems Plc

Group and these changes are purely changes of name and do not change any underlying legal

entities and hence will have no effect on any agreements or contacts currently in force.

CML Microcircuits Product Prefix Codes

Until the latter part of 1996, the differentiator between products manufactured and sold from

MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX

respectively. These products use the same silicon etc. and today still carry the same prefixes.

In the latter part of 1996, both companies adopted the common prefix: CMX.

This notification is relevant product information to which it is attached.

CML Microcircuits (USA) [formerly MX-COM, Inc.] Product Textual Marking

On CML Microcircuits (USA) products, the ‘MX-COM’ textual logo is being replaced by a ‘CML’

textual logo.

Company contact information is as below:

CML Microcircuits

(UK)Ltd

COMMUNICATION SEMICONDUCTORS

CML Microcircuits

COMMUNICATION SEMICONDUCTORS

CML Microcircuits

(Singapore)PteLtd

COMMUNICATION SEMICONDUCTORS

CML Microcircuits

(USA) Inc.

COMMUNICATION SEMICONDUCTORS

Oval Park, Langford, Maldon,

Essex, CM9 6WG, England

Tel: +44 (0)1621 875500

Fax: +44 (0)1621 875600

uk.sales@cmlmicro.com

www.cmlmicro.com

4800 Bethania Station Road,

Winston-Salem, NC 27105, USA

Tel: +1 336 744 5050,

0800 638 5577

Fax: +1 336 744 5054

us.sales@cmlmicro.com

www.cmlmicro.com

No 2 Kallang Pudding Road, 09-05/

06 Mactech Industrial Building,

Singapore 349307

Tel: +65 7450426

Fax: +65 7452917

sg.sales@cmlmicro.com

www.cmlmicro.com

D/CML (D)/2 May 2002

MX469P package discontinued